Yarn package



J MASSEY YARN PACKAGE Sept. 19, 1967 Filed Jan. 7, 1966 I nvenlor BZJe A/ Mmsm MMW A ttorney;

United States Patent Ofitice Great Britain Filed Jan. 7, 1966, Ser. No. 519,335 Claims priority, application Great Britain, Feb. 2, 1965, 4,443/ 65 3 Claims. (Cl. 242178) The present invention is concerned with improvements in or relating to yarn packages.

A yarn package comprises a build of yarn wound on a solid former, as for instance a bobbin or tube.

Yarn is often so wound at the termination of a treatment performed on it whilst the yarn is travelling from a supply thereof to the wind-up.

Continuous filament yarns of syntheic materials, like nylon for instance, are submitted to the treatment of drawing subsequently to their extrusion from the orifices of a spinneret. When wound up after this treatment, they are often wound into double taper packages, i.e. yarn packages having cylindrical. or symmetrically rounded middle portions and tapered end-portions. These double taper packages, particularly when built by a building motion starting with the greatest length of traverse stroke and finishing with the shortest length, are often used as the direct supply for textile machinery, as for instance knitting machines for womens hosiery.

In such a use, the take-oft characteristics are of vital importance. The tension imparted to the yarn by the act of with-drawing it over one end of the package should be as low as possible; and, perhaps even more importantly, it should at least approximate to being uniform throughout the period of withdrawal.

Such tension uniformity is to be considered in two differing aspects. Firstly, the variation of tension from start to finish of unwinding; and, secondly, local tension variations or snatches.

The nature of the package build is significant from both the above aspects. The yarn should not have to be withdrawn over a hump or shoulder of the package; and the surface from which the yarn is withdrawing at any given time should be homogeneous.

A build in which the traverse stroke is at the maximum length at the start of winding and which reduces gradually to the minim-um at the completion of winding generally meets the above criteria.

It is known to provide such a build in combination with a frusto-conical former, whereby the tension imparted to the yarn by the act of withdrawal is reduced below that experienced with a cylindrical former, in particular at the time of run-out.

From several respects, however, it is preferred that the formers on which the mass of yarn is wound shall be cylindrical.

Another matter which has some bearing on the takeoff characteristics is that of patterning in the build. Such patterning may occur due to the exact coinci-dence of adjacent coils at certain radii of the build, especially where ring tilt is employed when winding the the package on a ring spindle apparatus. Such ring tilt, say of 3-6 in amount, is usually so employed and serves, inter alia, to enhance the stability of the package.

It is an object of this inveniton to provide a double taper yarn package on a cylindrical former, to meet the general criteria for uniform withdrawal outlined above, and to minimise the risk of trouble arising from any patterning in the build.

According to the invention, a yarn package comprises continuous filament yarn wound on a cylindrical former 3,342,437 Patented Sept. 19, 1967 with a build having tapered end-portions in which build the innermost layer of yarn is of maximum length and the length of succeeding layers reduces gradually to minimum length at the outermost layer, and in which build the coils of yarn in each layer vary in mean spacing gradually from minimum spacing at the lowermost end of the layer to maximum spacing at the uppermost end, whereby the build has a mid-portion with sides tapering towards the upper end of the package.

Preferably, also, the yarn is wound in such a manner, erg. by means of ring tilt, that adjacent coils of yarn in each layer overlap one another at one or more points around each coil.

Optionally, the tapering end-portions of the build have frusto-conical (i.e. fiat) surfaces; and the surface of the mid-portion of the build tapering towards the upper end is likewise frusto-conical (i.e. flat).

The effect of the variation in helix angle of the coils and hence of the tapering of the mid-portion of the build, eg with a cone angle of 2, is to lower the tension in the yarn withdrawn from the package, especially during the earlier, main period of the withdrawal; and to cause any patterning that might be brought about to be spread over a number of layers, instead of appearing from top to bottom of the mid-portion of the build along one layer. The latter effect, which may be beneficial in lowering the already very low incidence of snatches, is due to the fact that patterning occurs at certain radii of the package and the tapering of the mid-portion of the build ensures that such radii will coincide with different thicknesses of the build along the length of that mid-portion.

The invention will now be described with reference to the accompanying drawings, in which FIGURE 1 is a diagrammatic elevational view, partly in section, of a yarn package according to the invention; and

FIGURE 2 is a diagrammatic elevational view of a ring spindle apparatus for use in producing a yarn package according to the invention.

In the drawings, a yarn package consists of a right cylindrical former 1, for instance a plastics sleeve mounted on a steel core, or an aluminium bobbin, and wound thereon a build of yarn 3. The yarn package has tapered end-portions 9, 11, and a mid-portion which itself tapers inwardly at a small angle, e.g. 2, towards the upper end of the yarn package.

As shown in the partly sectional portion of FIGURE 1, the build 3 is made up of layers of yarn, starting with a longest layer 5 next to the surface of the former 1 and finishing with an outermost layer 7 of least axial length.

FIGURE 2 depicts a yarn package being wound by a ring spindle apparatus comprising a traversing ring-rail 15 carrying a ring 13 which is angled at 3 to the horizontal, and a bobbin 1 mounted for rotation on an upstanding rotatable spindle (not shown) centrally disposed within the ring. Yarn Y from e.g. the draw roll of a drawtwister is led downwardly through balloon guide 17, and thence through a traveller (not shown) rotatable around ring 13. The yarn is wound into a build 3 in which adjacent coils overlap each other at certain points, due to the ring tilt applied to the ring, and such overlapping imparts extra stability to the build, particularly at the tapered endportions.

Yarn packages according to the invention may be produced at the termination of the process of draw-twisting nylon continuous filament yarn, eg of deniers from 15- 100, and of monofilament or multifilament nature. For example, a 4 lb. package (i.e. a package containing 4 lb. of yarn) may be wound with a ring tilt of 3 by means of a Rieter 15/5 hydraulic drawtwister.

The means whereby the tapering of the sides of the build is to be achieved can take any practicable form in which the traverse motion of the traverse guide, e.g. the ring of a drawtwister, is alternately accelerate-d and decelerated in phase with the to and fro, e.g. up and down, movement of the guide. On the Rieter 15/5 hydraulic drawtwister, it is necessary to vary the hydraulic speed control valve for the ring-rail motion; and this can simply be achieved by a cable drive from the balloon guide traverse (which rises and falls in phase with the package traverse) which drive is adapted to rotate the speed control valve knob. Other types of Rieter and other makers drawtwisters have intrinsic mechanism for accelerating and decelerating the traverse motion.

Nylon continuous filament yarn packages according to the invention have take-01f tensions, at least during the main period of the withdrawal, reduced by about compared with similar packages wound without tapered mid-portions. Tapers, i.e. cone angles, of up to about 3 are useful; higher than this angle, the package weight falls below what can normally be considered to be economic. It will be understood that cone angle, as used herein, denotes the angle between the axis and the inclined side of the package, that is, one-half the angle at the vertex of the cone.

I claim:

1. In a yarn package comprising continuous filament yarn wound on a cylindrical former with a build having tapered end-portions, in which build the innermost layer of yarn is of maximum length and the length of succeeding layers reduces gradually to a minimum length at the outermost layer, the improvement by which the coils of yarn in each layer of the build vary in mean spacing gradually from minimum spacing at the one end of the layer to maximum spacing at the other end, whereby the build has a mid-portion with sides tapering towards the end of the package where the coils of yarn have a maximum spacing therebetween.

2. A yarn package according to claim 1 in which adjacent coils of each layer overlap one another at one or more points around each coil.

3. A yarn package according to claim 2 in which the mid-portion of the build has sides which taper at an angle of 3 or less to the axis of the yarn package.

References Cited UNITED STATES PATENTS 1,214,741 2/1917 Altemus 242- 2,301,711 11/1942 Seem et a1. 242-178 2,764,363 9/1956 Stammwitz 24226.2 3,064,922 11/1962 Cochran 242-175 FOREIGN PATENTS 139,061 10/1950 Australia.

800,555 8/ 1958 Great Britain.

901,411 7/ 1962 Great Britain.

566,962 2/ 1956 Italy.

STANLEY N. GILREATH, Primary Examiner. 

1. IN A YARN PACKAGE COMPRISING CONTINUOUS FILAMENT YARN WOUND ON A CYLINDRICAL FORMER WITH A BUILD HAVING TAPERED END-PORTIONS, IN WHICH THE INNERMOST LAYER OF YARN IS OF MAXIMUM LENGTH AND THE LENGTH OF SUCCEEDING LAYERS REDUCES GRADUALLY TO A MINIMUM LENGTH AT THE OUTERMOST LAYER, THE IMPROVEMENT BY WHICH THE COILS OF YARN IN EACH LAYER OF THE BUILD VARY IN MEANS SPACING GRAD- 